Tangent bending machine



June 23, 1964 s. M. DOLNEY TANGENT BENDING MACHINE .3 Sheets-Sheet l mm Qm mm Filed March 2, 1961 INVENTOR. 72/- $40 Arne/v5) June 23, 1964 s. M. DOLNEY 3,133,192

TANGENT BENDING MACHINE Filed March 2. 1961 .3 Sheets-Sheet 2 IN V N TOR.

I 5 ATTJEA/EK s. M. DOLNEY 3,138,192

TANGENT BENDING MACHINE I5 Sheets-Sheet 3 INVZ NTOR. 52' N A410 ATmP/vn June 23, 1964 Filed March 2, 1961 United States Patent 3,138,192 TANGENT BENDING MACHINE Stanley M. Dolney, Par-ma, Ohio, assignor to The Cyril Bath Company, Solon, Ohio, a corporation of Ohio Filed Mar. 2, 1961, Ser. No. 92,797 8 Claims. (ill. 153--1$) This invention relates to a tangent bending machine, and more particularly to a tangent bending machine for forming in sheet metal stock a plurality of successive parallel bends extending transversely of the length of the stock and spaced from each other endwise of the stock.

Prior tangent bending machines of the above type usually include an elongated anvil die having a bottom face adapted to engage one face of a length of stock between the ends of the stock, and having side faces and a top face about which latter faces the stock is wrapped by successively bending it about the edges defined by the intersections of adjacent faces. The bending is effected by a plurality of bending wing dies pivotally mounted on wing carriers swingable toward the side faces of the anvil die about axes parallel to, and close to, the intersections of the faces. Usually, separate wing carriers are arranged adjacent the side faces, respectively, each wing carrier having a lower bending wing die for bending the workpiece around the edge defined by the intersection of the bottom face and side face, and an upper bending wing die for bending the stock about the edge defined by the intersection of the top face and side face. Clamping or holding members are provided on the wing carriers for suitably clamping the workpiece against the side faces of the anvil die prior to bending of the stock about the latter edges, respectively.

In such prior structures, the speed, flexibility, and efficiency in operation of each wing carrier is limited due to its excessive weight and the weight resulting from the plurality of bending wing dies and clamping members disposed thereon. Also, with two or more bending wing dies on a single wing carrier, adjustment of each bending wing die for effective bending of the stock is directly dependent on the adjustment of the other bending wing die on such carrier Thus, one die cannot be adjusted independently of the other die on the same carrier. Additionally, although the anvil die is adapted to receive bending die plates of different sizes, the range of such sizes is substantially limited, with the result that only stock of relatively limited length may be bent in such prior structures.

An object of the present invention is to provide a tangent bending machine that is fast and flexible in operation in comparison with prior structures.

A further object of the invention is to provide a bending machine wherein each wing carrier carries only one bending wing die and hence can be made lighter than in prior structures.

A further object of the invention is to provide a bending machine wherein each of the bending wing dies may be adjusted for effective bending independently of the adjustment of the other dies.

A further object of the invention is to provide a tangent bending machine having an anvil die composed of two separable portions disposed in spaced relation to each other endwise of the stock and movable toward and away from each other to accommodate stock of a wide range of lengths.

In the illustrative example, the foregoing objects are accomplished by the provision of a horizontal tangent bending machine having an elongated two-part anvil die, having'top, bottom, and side forming faces and spaced above and movable towards a work support or platen for effecting work clamping cooperation of the machine embodying the principles of the present inven- "ice bottom forming face therewith. The anvil die side face and top and bottom faces define a pair of lower edges and a pair of upper edges, all of which extend transversely of the stock and around which the stock may be bent.

A first bending wing die is pivotally mounted directly on the support for swinging movement around the lower transverse edge of the anvil die about an axis parallel to, and closely adjacent to, said edge for bending a portion of the stock thereabout. A second wing die carrier is pivotally mounted also on the support for movement independently of the first Wing die carrier toward the upper transverse edge defined by the intersection of the side face and top face of the anvil die to an operative position adjacent the upper edge. A second bending wing die is mounted on the second wing die carrier for swinging movement relative to the carrier about an axis which, when the second carrier is in its uppermost position, is parallel to, and closely adjacent to, the upper edge of the anvil die, for bending another portion of the workpiece around such upper edge while the carrier is disposed in said upper operating position. With this construction, each carrier and each bending wing die is mounted and operates independently of the other, such that operative adjustment of one such die will not affect the adjustment of the other die. Since each carrier has only one wing bending die, it can itself be made lighter in weight'than if it were to carry two dies. Thus, in each instance, only one die and a lighter carrier is swung to positions and the moments of inertia are greatly reduced. Accordingly, operative speed and efiiciency of the carrier are substantially increased.

The two separable portions of the anvil die, each with its first wing die carrier, first wing die, second wing die carrier, and second wing die, are mountedon a common support for movement toward and away from each other endwise of the stock to different spaced positions relative to each other for receiving sheets of stock of dif ferent lengths. With this construction, the stock can be bent around both portions of the anvil die simultaneously.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the drawings, wherein:

FIG. 1 is a front elevational view of a tangent bending tion;

FIG. 2 is a top plan view of the machine illustrated in FIG. 1;

FIG. 3 is a left end elevational view of the machine illustrated in FIG. 1, taken on the line 3-3 in FIG. 1; and

FIG. 4 is a reduced perspective view showing a length of stock which has been bent into O-shape cross section by the machine illustrated in FIG. 1.

The machine incorporating two separable anvil die portions is, in efifect, two substantially identical tangent bending machine structures, designated generally as A and B, which may function independently or in coaction with each other, hence a description of one will suffice for a description of both. Since'the two structures are the same, the parts of structure B are identified by numerals only, and the corresponding parts of structure A are identified by the same numerals as used on structure B, but followed by the sufiix a.

The bending machine structure B, in the preferred form, includes a suitable work supporting frame or support 10 having an upper horizontal table or surface supporting a female die 11 in which a planular elongated sheet of metal S is to be formed. An upright frame portion 16 is located at the rear of the frame 10 at an intermediate point thereof.

The upright frame 16 has a forwardly extending frame portion or anvil die support arm 17 which supports the anvil die unit, generally designated as 18, in spaced relation over the die 11. The rear portion 22 of the arm 17 is formed to fit slidably into vertical slots or tracks 23 in the upright frame 16 such that the anvil die 18 is vertically movable toward and away from the die 11 to form the sheet S. Such vertical displacement of the anvil die may be effected by suitable power means such as, for example, the hydraulic double-acting anvil die piston and cylinder assemblage 24, including a cylinder 25, piston 26, and piston rod 27. The lower end of the rod 27 is secured to a plate 29 which is fastened to the rear portion 22 of the anvil die support arm 17 The anvil die 18 comprises two separable portions, each of which is in the form of a generally box-like frame 30 disposed transversely of the support or of the length of stock S. The frame includes a top face 31, a bottom face 32, and an outer side face 33, the intersections of said bottom and top faces being horizontal and parallel to each other and extending transversely of the length of stock.

The anvil die carries an elongated lower male bending die plate 34 having a portion overlying the bottom face of the anvil die and an upright portion overlying the outer face of the anvil die adjacent the lower edge of the anvil die. A similar elongated upper male die plate 36 is arranged at the upper outer edge of the anvil die and overlies a portion of the outer side face of the anvil die adjacent the upper edge and a portion of the upper face 31 of the anvil die adjacent the outer edge. The stock S is formed by bending it successively about the outer faces of such die plates, as will be hereinafter described. The die plates 34 and 36 are L-shaped in cross section and their outer faces intersect to form the lower and upper outer bending edges 38 and 39, respectively. These edges are outwardly curvilinear and convex about horizontal parallel axes close to the intersections of the faces, and extending transversely of the stock, to facilitate bending of the stock therearound.

Outer portions Sd and Se of the stock S initially extend in opposite directions from an intermediate portion Sf which is clamped between the die plate 34 and die 11 when the anvil die 18 is lowered to forming position. The portions Sd and Se are bent upwardly and around the outer lower and upper edges of the anvil dies to form the stock into O-shape cross section, as shown in FIG. 4.

In carrying out this operation, the outer portions Sd and Se of the stock are bent into conformity to outer faces of the anvil die plates 34 and 34a to form the bends Sh and Si, respectively, and thence are bent around into conformity to the outer faces of the upper anvil die plates 36 and 36a to form the bends Sj and Sk, respectively. The bending of the outer portions Sd and Se of the stock around the anvil die is accomplished by pivotal wing bending dies and 46. These dies bend the workpiece portion Sd around the anvil die portion 18. Pivotal wing bending dies 45a and 46a bend the stock Se around the anvil die portion 18a.

The first wing bending die 45 has a planular forming face which is elongated transversely of the support and has upturned flanges at its lateral margins. It is mounted on an elongated first wing die carrier 47. The carrier 47 extends transversely on the frame 10 and is pivotally secured at each of its end portions 48 to spaced support brackets 50. The brackets 50 are rigidly secured to the top surface of the support 10. It is to be noted that the carrier 47 is mounted on the support 10 for swinging upwardly about an axis 51 which is parallel to the lower bending edge 38 of the die plate 34. This axis is disposed inwardly of the anvil die 18 from. the edge 33 and from the bottom face 55 and end face 56 of the die plate 34, and is preferably coincident with the axis of curvature of the lower edge 38. Thus, the wing bending die 45 is pivotally mounted to rock around the edge 38 while progressively pressing and forming the stock portion Sd therearound and into conformity with the edge 38 and the adjacent outer side face portion 56 of the plate 34.

Pivotal rocking of the carrier 47 and its bending die 45 may be effected by any suitable power means, such as the double-acting hydraulic piston and cylinder assemblage 57, the lower end of which is pivotally secured to a bracket 58 on the support 10. The assemblage includes a reciprocable piston 59 having a rod 60, the upper end of which is pivotally secured to a bracket 61 on the carrier 47. With this construction, actuation of the assemblage 57 to extended position causes the bending die 45 to pivot or rock about the lower edge 38 of the anvil die plate 34 and thus press and form the stock S therearound, as aforedescribed.

Bending of the stock S about the upper edge 39 of the anvil die plate 36 is effected by the second bending wing die 46 and its supporting structure, now to be described. The die 46 is pivotally mounted on a rocking wing die carrier, generally designated as 66. The carrier 66 comprises a planular elongated plate 67 extending transversely or" the support 10 and having its outer ends rigidly secured to the outer ends of spaced parallel side frames or arms '79. The plate 67 and the arms 70 form a single, unitary, rigid structure. The inner ends of the arms 70 are pivotally secured to the brackets 50 exteriorly thereof for swinging about an axis which may be coincident with the axis 51. Thus, the carrier 66 pivots on the support 10 about a horizontal axis extending transversely of the length of stock and parallel to the edge 38 defined by intersections of the outer forming faces of theplates 34. The carrier swings from a lower operating position to an upper operating position.

The bending die 46 is an elongated member extending transversely of the support 10 and having a planular forming face with upturned flanges at its lateral margins. It is pivotally secured at its end portions 75 to the outer ends of the spaced parallel arms 70. Thus, the bending die 46 pivots on the carrier 66 about an axis parallel to the pivotal axis of the carrier 66.

The die 46 is rotated on the carrier 66 by the doubleacting hydraulic piston and cylinder assemblage 77 having a cylinder 78 and piston 79 with a rod 80. The rod 80 is pivotally secured to a bracket 81 on the carrier 66. The inner end of the cylinder is pivotally secured to a triangular bracket 82 on the die 46.

Pivotal rotation of the carrier 66 may be accomplished by any suitable power means such as the spaced, doubleacting, hydraulic piston and cylinder assemblages 84, each including a cylinder 85, piston 86, and piston rod 87. The lower ends of the cylinders are pivotally secured to the brackets 88, respectively, on the support 10. The upper ends of the piston rods 87 are pivotally secured to the respective triangular brackets 89 on the carrier 66.

Actuation of the cylinders causes the carrier 66 to swing upwardly to an upper operative bending position. Thence, the wing die piston and cylinder assemblage 77 is actuated to cause the wing die 46 to rock about the upper edge 39 of the anvil die plate and progressively press and form the stock into conformity to said upper edge and the adjacent outer side face portion and upper face portion of the die plate 36.

A suitable hold-down or clamping member 90 is disposed on the carrier 66 to firmly clamp the stock against the outer side face of the die plate 36 preparatory to the bending operation of the die 46. The hold-down member 90 is positioned outwardly from the rocking axis beyond the first wing die 45 for so engaging or clamping the stock and holding it against the outer side face of the plate 36 at a location above the lower edge 38 and below the upper edge 39.

It will be noted that the support 10a is slidably mounted on spaced support parallel beams 92 for sliding movement toward and away from the support 10 for adjusting the anvil die portions 18 and 18a for handling various lengths of stock. Such sliding movement of the support 10a may be effected by any suitable means, such as a feed screw 93 which is secured at one end to the support and which operatively engages an internally threaded follower 94 rigidly secured to the support 10a, as shown in FIG. 1. Rotation of the screw 93 causes the support 10a to move along its support, beams 92 in a direction depending on the direction of rotation of the screw 93.

Thus, the supports 10 and 10a and their anvil die portions 18 and 18a, respectively, are positioned so that the anvil die portions are aligned endwise of the stock with the bending edges 38 and 39 of the plates 34 and 36 of the anvil die 18 being exposed outwardly and paral lel to each other and parallel to the bending edges 38a and 39a, respectively, of the plates 34a and 36a of the anvil die 18a.

For most effective operation, the rocking axes of the carriers 47 and 66 are substantially coincident with the axis of curvature of the lower edge 38 of the anvil die plate 34, and the rocking axis of the wing die 46, when the carrier 66 is in its upper position, is substantially coincident with the axis of curvature of the upper edge 39 of the anvil die plate 36.

Thus a sheet of stock can be formed by gripping it between the male and female dies on the anvil die and support, respectively, the sheet being flanged along the margins of the portion thus gripped. Next, the carriers for the respective wing dies are operated, the wing die 45 forming the stock about the edge 38 and concurrently forming the marginal flange thereon as the remainder of the stock is lifted by the carrier 66. The outer end portion of the stock is moved into position and held against the outer face of the plate 36 by the hold-down member 90 when the carrier 66 is in its upper operating position, and the free end portion of the stock beyond the holddown member 90 is then bent about the upper die plate 36 by the wing die 46. A length of stock is usually such that when thus folded into O-shaped cross section, the free edges of its ends are closely adjacent each other and can be readily welded together.

Having thus described my invention, 1 claim:

1. A bending machine comprising:

a frame;

a work support having a supporting face for receiving and supporting thereon an associated length of sheet stock to be bent;

an anvil die mounted on the frame and having a face facing toward, spaced from, and movable toward, the support into work clamping cooperation with the supporting face, said anvil die having a first bending edge disposed immediately adjacent the face of the support when the die and support faces are in said clamping cooperation and having a second bending edge spaced substantially from the support when the die and support faces are in said clamping cooperation;

means for moving the anvil die toward and away from the support to dispose said faces in said clamping cooperation and to dispose them in open position, respectively;

a first wing die carrier pivotally mounted on the frame for swinging movement around said first edge, said wing die carrier having a first wing die mounted thereon and carried thereby and operative to bend a portion of the stock about said first edge when the first wing die carrier is swung to operative position;

a first power means for imparting said swinging movement to said first wing die carrier;

a second wing die carrier pivotally mounted on the frame, separate and apart from the first wing die carrier so that the second wing die carrier can be swung toward said second edge, independently of the movement of the first wing die carrier, to a predetermined operating position;

second power means operable independently of the 6 first power means for swinging the second wing die carrier toward and away from the second edge;

a second wing die pivotally mounted on the second wing die carrier for swinging movement, relative to the second wing die carrier, around said second edge to bend another portion of the stock around said second edge while the second wing die carrier is disposed in said predetermined operating position;

and third power means for imparting said swinging movement of said second wing die relativeto the second Wing die carrier.

2. The structure of claim 1 wherein a holddown member is disposed on said second wing die carrier for clamping the stock against the anvil die at a point intermediate the edges thereof prior to and during the second bending operation.

3. The structure of claim 1 wherein the pivotal axis of the first wing die carrier is closely adjacent to, and substantially parallel to, said first edge, and the second wing die carrier is pivotally mounted on the frame for swinging movement to its said operating position about an axis parallel to, and substantially coincident with, said pivotal axis of the first wing die carrier, whereby the upper portion of the second wing die carrier is disposed immediately adjacent said second edge of the anvil die when the second wing die carrier is swung to such upper position.

4. A bending machine comprising:

a frame;

a work supporting bed;

an anvil die supported on the frame for movement toward and away from the bed;

power means to move the anvil die toward and away from the bed;

said anvil die having a bottom face, a side face, and a top face, said top and bottom faces defining with the side face at one side of the anvil die an upper edge and a lower edge, respectively, said edges extending transversely of the bed;

a first wing die carreir mounted on the frame for rocking about an axis which is parallel to the lower edge and is disposed inwardly of the anvil die from the bottom and side faces thereof when the anvil die is in closed position;

a first wing die carried on the rockable carrier and rocked thereby around said lower edge while progressively pressing and forming an associated length of sheet stock into conformity to said lower edge and the adjacent portion of the end face;

a second wing die carrier mounted on the frame, separate and apart from the first carrier, for movement relative to the first carrier to a predetermined operating position adjacent said upper edge;

a second wing die mounted on the second carrier for rocking about an axis which, in the operating position of the second carrier while the anvil die is in closed position, is parallel to the upper edge and is.

power means for operating the carriers, respectively;

and additional power means on the second carrier to operate the second wing die.

5. A bending machine according to claim 4 wherein a holder is mounted on the second wing die carrier and is positioned outwardly from the rocking axis beyond the second wing die for engaging the stock and holding it against the side face of the anvil die at a location spaced from said upper edge.

6. The structure of claim 4 wherein the second wing die carrier is mounted on the frame for rocking movement relative to the first wing die carrier about the rocking axis of the first wing die carrier.

7. The structure of claim 6 wherein:

the edges of the anvil die are outwardly curvilinear 7 8 and convex about axes close to the edges, respec- References Cited in the file of this patent vely; UNITED STATES PATENTS the rocking axis of the carriers is substantially coincident with the axis of curvature of the lower edge; 5361450 Adams 1895 and the rocking axis of the second Wing die, when the 5 1,323,143 9 251 1919 second wing die carrier is in operating position, is 2,225,187 Sun et 1940 substantially coincident with the axis of curvature of 2552617 Bath May 1951 2,557,346 Green June 19, 1951 the upper edge.

2,596,848 Green May 13, 1952 8. The structure according to claim 7 wherein the second wing die carrier comprises a pair of side frames. 10 

1. A BENDING MACHINE COMPRISING: A FRAME; A WORK SUPPORT HAVING A SUPPORTING FACE FOR RECEIVING AND SUPPORTING THEREON AN ASSOCIATED LENGTH OF SHEET STOCK TO BE BENT; AN ANVIL DIE MOUNTED ON THE FRAME AND HAVING A FACE FACING TOWARD, SPACED FROM, AND MOVABLE TOWARD, THE SUPPORT INTO WORK CLAMPING COOPERATION WITH THE SUPPORTING FACE, SAID ANVIL DIE HAVING A FIRST BENDING EDGE DISPOSED IMMEDIATELY ADJACENT THE FACE OF THE SUPPORT WHEN THE DIE AND SUPPORT FACES ARE IN SAID CLAMPING COOPERATION AND HAVING A SECOND BENDING EDGE SPACED SUBSTANTIALLY FROM THE SUPPORT WHEN THE DIE AND SUPPORT FACES ARE IN SAID CLAMPING COOPERATION; MEANS FOR MOVING THE ANVIL DIE TOWARD AND AWAY FROM THE SUPPORT TO DISPOSE SAID FACES IN SAID CLAMPING COOPERATION AND TO DISPOSE THEM IN OPEN POSITION, RESPECTIVELY; A FIRST WING DIE CARRIER PIVOTALLY MOUNTED ON THE FRAME FOR SWINGING MOVEMENT AROUND SAID FIRST EDGE, SAID WING DIE CARRIER HAVING A FIRST WING DIE MOUNTED THEREON AND CARRIED THEREBY AND OPERATIVE TO BEND A PORTION OF THE STOCK ABOUT SAID FIRST EDGE WHEN THE FIRST WING DIE CARRIER IS SWUNG TO OPERATIVE POSITION; A FIRST POWER MEANS FOR IMPARTING SAID SWINGING MOVEMENT TO SAID FIRST WING DIE CARRIER; A SECOND WING DIE CARRIER PIVOTALLY MOUNTED ON THE FRAME, SEPARATE AND APART FROM THE FIRST WING DIE CARRIER SO THAT THE SECOND WING DIE CARRIER CAN BE SWUNG TOWARD SAID SECOND EDGE, INDEPENDENTLY OF THE MOVEMENT OF THE FIRST WING DIE CARRIER, TO A PREDETERMINED OPERATING POSITION; SECOND POWER MEANS OPERABLE INDEPENDENTLY OF THE FIRST POWER MEANS FOR SWINGING THE SECOND WING DIE CARRIER TOWARD AND AWAY FROM THE SECOND EDGE; A SECOND WING DIE POVITALLY MOUNTED ON THE SECOND WING DIE CARRIER FOR SWINGING MOVEMENT, RELATIVE TO THE SECOND WING DIE CARRIER, AROUND SAID SECOND EDGE TO BEND ANOTHER PORTION OF THE STOCK AROUND SAID SECOND EDGE WHILE THE SECOND WING DIE CARRIER IS DISPOSED IN SAID PREDETERMINED OPERATING POSITION; AND THIRD POWER MEANS FOR IMPARTING SAID SWINGING MOVEMENT OF SAID SECOND WING DIE RELATIVE TO THE SECOND WING DIE CARRIER. 